Re: [CAD_CAM_EDM_DRO] Interesting, 3 phase in the UK

John wrote:

> Hello all,
>
> I called British Gas & Electricity today to ask them about 3 phase, they said I should call Manweb. I did just that and apparently they'll run three phase electricity into your house for free, in fact the woman was getting ready to sign me up for it before I'd finished asking my question. You need to get a 3 phase power meter from your supplier. I'm currently finding out how much one of these will cost and I'm not sure if you can still get the standard single phase at the moment.

If they do things about the same as here in the US, you should be able to get
a "Wye" service, or 5-wire service, that has a neutral, as well as a safety ground.
In the US, the most common low-voltage 3-phase service for mixed uses (ie.
office building, small shop, etc.) is 208 V 3-phase, which has 120 V from neutral
to any line. You can run 120 V appliances and 208 V 3-phase loads directly.
The only problem is that you can't get 240 V directly from this service.
Many air conditioners are designed for 208-230 V single phase, and can be
used on this service.

Unfortunately, this doesn't work out so well for most other countries, as they
use 220 V single-phase appliances. I suppose there might be a 220 / 416 V
service that will run your 3-phase motors as well as the usual appliances.

> I just thought some of you guys might be interested in what I've found out, even though it's not strictly CNC related, there are lots of machines out there that are going to waste that run on three phase and it seems that a couple of places charge you for having a three phase line put in. An when you can have the true three phase run in for free it kind of negates the need for a VFD unless you want the spindle control (And even then it's cheaper than buying one to convert the single phase 220 to 440). I forgot to ask what voltage this line will be at.

Umm, you'd better find out before ripping out the old wiring. By the way, it most likely
will require ripping out your entire circuit breaker panel all the way out to the pole, and
replacing with 3-phase service entry parts. That is where it is going to cost you.

Jon